Module: ActionView::Helpers::FormHelper

Extended by:
ActiveSupport::Concern
Includes:
FormTagHelper, UrlHelper
Included in:
ActionView::Helpers
Defined in:
actionpack/lib/action_view/helpers/form_helper.rb

Overview

Form helpers are designed to make working with resources much easier compared to using vanilla HTML.

Forms for models are created with form_for. That method yields a form builder that knows the model the form is about. The form builder is thus able to generate default values for input fields that correspond to model attributes, and also convenient names, IDs, endpoints, etc.

Conventions in the generated field names allow controllers to receive form data nicely structured in params with no effort on your side.

For example, to create a new person you typically set up a new instance of Person in the PeopleController#new action, @person, and pass it to form_for:

<%= form_for @person do |f| %>
  <%= f.label :first_name %>:
  <%= f.text_field :first_name %><br />

  <%= f.label :last_name %>:
  <%= f.text_field :last_name %><br />

  <%= f.submit %>
<% end %>

The HTML generated for this would be (modulus formatting):

<form action="/people" class="new_person" id="new_person" method="post">
  <div style="margin:0;padding:0;display:inline">
    <input name="authenticity_token" type="hidden" value="NrOp5bsjoLRuK8IW5+dQEYjKGUJDe7TQoZVvq95Wteg=" />
  </div>
  <label for="person_first_name">First name</label>:
  <input id="person_first_name" name="person[first_name]" size="30" type="text" /><br />

  <label for="person_last_name">Last name</label>:
  <input id="person_last_name" name="person[last_name]" size="30" type="text" /><br />

  <input name="commit" type="submit" value="Create Person" />
</form>

As you see, the HTML reflects knowledge about the resource in several spots, like the path the form should be submitted to, or the names of the input fields.

In particular, thanks to the conventions followed in the generated field names, the controller gets a nested hash params[:person] with the person attributes set in the form. That hash is ready to be passed to Person.create:

if @person = Person.create(params[:person])
  # success
else
  # error handling
end

Interestingly, the exact same view code in the previous example can be used to edit a person. If @person is an existing record with name “John Smith” and ID 256, the code above as is would yield instead:

<form action="/people/256" class="edit_person" id="edit_person_256" method="post">
  <div style="margin:0;padding:0;display:inline">
    <input name="_method" type="hidden" value="put" />
    <input name="authenticity_token" type="hidden" value="NrOp5bsjoLRuK8IW5+dQEYjKGUJDe7TQoZVvq95Wteg=" />
  </div>
  <label for="person_first_name">First name</label>:
  <input id="person_first_name" name="person[first_name]" size="30" type="text" value="John" /><br />

  <label for="person_last_name">Last name</label>:
  <input id="person_last_name" name="person[last_name]" size="30" type="text" value="Smith" /><br />

  <input name="commit" type="submit" value="Update Person" />
</form>

Note that the endpoint, default values, and submit button label are tailored for @person. That works that way because the involved helpers know whether the resource is a new record or not, and generate HTML accordingly.

The controller would receive the form data again in params[:person], ready to be passed to Person#update_attributes:

if @person.update_attributes(params[:person])
  # success
else
  # error handling
end

That’s how you typically work with resources.

Constant Summary

Constants included from TagHelper

TagHelper::BOOLEAN_ATTRIBUTES, TagHelper::PRE_CONTENT_STRINGS

Instance Method Summary collapse

Methods included from ActiveSupport::Concern

append_features, extended, included

Methods included from UrlHelper

#_routes_context, #button_to, #current_page?, #link_to, #link_to_if, #link_to_unless, #link_to_unless_current, #mail_to, #url_for, #url_options

Methods included from TagHelper

#cdata_section, #content_tag, #escape_once, #tag

Methods included from CaptureHelper

#capture, #content_for, #content_for?, #flush_output_buffer, #provide, #with_output_buffer

Methods included from ActionDispatch::Routing::UrlFor

#initialize, #url_for, #url_options

Methods included from ActionDispatch::Routing::PolymorphicRoutes

#polymorphic_path, #polymorphic_url

Methods included from FormTagHelper

#button_tag, #check_box_tag, #email_field_tag, #field_set_tag, #file_field_tag, #form_tag, #hidden_field_tag, #image_submit_tag, #label_tag, #number_field_tag, #password_field_tag, #radio_button_tag, #range_field_tag, #search_field_tag, #select_tag, #submit_tag, #telephone_field_tag, #text_area_tag, #text_field_tag, #url_field_tag, #utf8_enforcer_tag

Methods included from TextHelper

#concat, #current_cycle, #cycle, #excerpt, #highlight, #pluralize, #reset_cycle, #safe_concat, #simple_format, #truncate, #word_wrap

Methods included from SanitizeHelper

#sanitize, #sanitize_css, #strip_links, #strip_tags

Instance Method Details

#check_box(object_name, method, options = {}, checked_value = "1", unchecked_value = "0") ⇒ Object

Returns a checkbox tag tailored for accessing a specified attribute (identified by method) on an object assigned to the template (identified by object). This object must be an instance object (@object) and not a local object. It’s intended that method returns an integer and if that integer is above zero, then the checkbox is checked. Additional options on the input tag can be passed as a hash with options. The checked_value defaults to 1 while the default unchecked_value is set to 0 which is convenient for boolean values.

Gotcha

The HTML specification says unchecked check boxes are not successful, and thus web browsers do not send them. Unfortunately this introduces a gotcha: if an Invoice model has a paid flag, and in the form that edits a paid invoice the user unchecks its check box, no paid parameter is sent. So, any mass-assignment idiom like

@invoice.update_attributes(params[:invoice])

wouldn’t update the flag.

To prevent this the helper generates an auxiliary hidden field before the very check box. The hidden field has the same name and its attributes mimic an unchecked check box.

This way, the client either sends only the hidden field (representing the check box is unchecked), or both fields. Since the HTML specification says key/value pairs have to be sent in the same order they appear in the form, and parameters extraction gets the last occurrence of any repeated key in the query string, that works for ordinary forms.

Unfortunately that workaround does not work when the check box goes within an array-like parameter, as in

<%= fields_for "project[invoice_attributes][]", invoice, :index => nil do |form| %>
  <%= form.check_box :paid %>
  ...
<% end %>

because parameter name repetition is precisely what Rails seeks to distinguish the elements of the array. For each item with a checked check box you get an extra ghost item with only that attribute, assigned to “0”.

In that case it is preferable to either use check_box_tag or to use hashes instead of arrays.

Examples

# Let's say that @post.validated? is 1:
check_box("post", "validated")
# => <input name="post[validated]" type="hidden" value="0" />
#    <input type="checkbox" id="post_validated" name="post[validated]" value="1" />

# Let's say that @puppy.gooddog is "no":
check_box("puppy", "gooddog", {}, "yes", "no")
# => <input name="puppy[gooddog]" type="hidden" value="no" />
#    <input type="checkbox" id="puppy_gooddog" name="puppy[gooddog]" value="yes" />

check_box("eula", "accepted", { :class => 'eula_check' }, "yes", "no")
# => <input name="eula[accepted]" type="hidden" value="no" />
#    <input type="checkbox" class="eula_check" id="eula_accepted" name="eula[accepted]" value="yes" />



842
843
844
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 842

def check_box(object_name, method, options = {}, checked_value = "1", unchecked_value = "0")
  InstanceTag.new(object_name, method, self, options.delete(:object)).to_check_box_tag(options, checked_value, unchecked_value)
end

#convert_to_model(object) ⇒ Object

Converts the given object to an ActiveModel compliant one.



109
110
111
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 109

def convert_to_model(object)
  object.respond_to?(:to_model) ? object.to_model : object
end

#email_field(object_name, method, options = {}) ⇒ Object

Returns a text_field of type “email”.

email_field("user", "address")
# => <input id="user_address" size="30" name="user[address]" type="email" />



931
932
933
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 931

def email_field(object_name, method, options = {})
  InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("email", options)
end

#fields_for(record_name, record_object = nil, options = {}, &block) ⇒ Object

Creates a scope around a specific model object like form_for, but doesn’t create the form tags themselves. This makes fields_for suitable for specifying additional model objects in the same form.

Generic Examples

<%= form_for @person do |person_form| %>
  First name: <%= person_form.text_field :first_name %>
  Last name : <%= person_form.text_field :last_name %>

  <%= fields_for @person.permission do |permission_fields| %>
    Admin?  : <%= permission_fields.check_box :admin %>
  <% end %>

  <%= f.submit %>
<% end %>

…or if you have an object that needs to be represented as a different parameter, like a Client that acts as a Person:

<%= fields_for :person, @client do |permission_fields| %>
  Admin?: <%= permission_fields.check_box :admin %>
<% end %>

…or if you don’t have an object, just a name of the parameter:

<%= fields_for :person do |permission_fields| %>
  Admin?: <%= permission_fields.check_box :admin %>
<% end %>

Note: This also works for the methods in FormOptionHelper and DateHelper that are designed to work with an object as base, like FormOptionHelper#collection_select and DateHelper#datetime_select.

Nested Attributes Examples

When the object belonging to the current scope has a nested attribute writer for a certain attribute, fields_for will yield a new scope for that attribute. This allows you to create forms that set or change the attributes of a parent object and its associations in one go.

Nested attribute writers are normal setter methods named after an association. The most common way of defining these writers is either with accepts_nested_attributes_for in a model definition or by defining a method with the proper name. For example: the attribute writer for the association :address is called address_attributes=.

Whether a one-to-one or one-to-many style form builder will be yielded depends on whether the normal reader method returns a single object or an array of objects.

One-to-one

Consider a Person class which returns a single Address from the address reader method and responds to the address_attributes= writer method:

class Person
  def address
    @address
  end

  def address_attributes=(attributes)
    # Process the attributes hash
  end
end

This model can now be used with a nested fields_for, like so:

<%= form_for @person do |person_form| %>
  ...
  <%= person_form.fields_for :address do |address_fields| %>
    Street  : <%= address_fields.text_field :street %>
    Zip code: <%= address_fields.text_field :zip_code %>
  <% end %>
  ...
<% end %>

When address is already an association on a Person you can use accepts_nested_attributes_for to define the writer method for you:

class Person < ActiveRecord::Base
  has_one :address
  accepts_nested_attributes_for :address
end

If you want to destroy the associated model through the form, you have to enable it first using the :allow_destroy option for accepts_nested_attributes_for:

class Person < ActiveRecord::Base
  has_one :address
  accepts_nested_attributes_for :address, :allow_destroy => true
end

Now, when you use a form element with the _destroy parameter, with a value that evaluates to true, you will destroy the associated model (eg. 1, ‘1’, true, or ‘true’):

<%= form_for @person do |person_form| %>
  ...
  <%= person_form.fields_for :address do |address_fields| %>
    ...
    Delete: <%= address_fields.check_box :_destroy %>
  <% end %>
  ...
<% end %>

One-to-many

Consider a Person class which returns an array of Project instances from the projects reader method and responds to the projects_attributes= writer method:

class Person
  def projects
    [@project1, @project2]
  end

  def projects_attributes=(attributes)
    # Process the attributes hash
  end
end

Note that the projects_attributes= writer method is in fact required for fields_for to correctly identify :projects as a collection, and the correct indices to be set in the form markup.

When projects is already an association on Person you can use accepts_nested_attributes_for to define the writer method for you:

class Person < ActiveRecord::Base
  has_many :projects
  accepts_nested_attributes_for :projects
end

This model can now be used with a nested fields_for. The block given to the nested fields_for call will be repeated for each instance in the collection:

<%= form_for @person do |person_form| %>
  ...
  <%= person_form.fields_for :projects do |project_fields| %>
    <% if project_fields.object.active? %>
      Name: <%= project_fields.text_field :name %>
    <% end %>
  <% end %>
  ...
<% end %>

It’s also possible to specify the instance to be used:

<%= form_for @person do |person_form| %>
  ...
  <% @person.projects.each do |project| %>
    <% if project.active? %>
      <%= person_form.fields_for :projects, project do |project_fields| %>
        Name: <%= project_fields.text_field :name %>
      <% end %>
    <% end %>
  <% end %>
  ...
<% end %>

Or a collection to be used:

<%= form_for @person do |person_form| %>
  ...
  <%= person_form.fields_for :projects, @active_projects do |project_fields| %>
    Name: <%= project_fields.text_field :name %>
  <% end %>
  ...
<% end %>

When projects is already an association on Person you can use accepts_nested_attributes_for to define the writer method for you:

class Person < ActiveRecord::Base
  has_many :projects
  accepts_nested_attributes_for :projects
end

If you want to destroy any of the associated models through the form, you have to enable it first using the :allow_destroy option for accepts_nested_attributes_for:

class Person < ActiveRecord::Base
  has_many :projects
  accepts_nested_attributes_for :projects, :allow_destroy => true
end

This will allow you to specify which models to destroy in the attributes hash by adding a form element for the _destroy parameter with a value that evaluates to true (eg. 1, ‘1’, true, or ‘true’):

<%= form_for @person do |person_form| %>
  ...
  <%= person_form.fields_for :projects do |project_fields| %>
    Delete: <%= project_fields.check_box :_destroy %>
  <% end %>
  ...
<% end %>



605
606
607
608
609
610
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 605

def fields_for(record_name, record_object = nil, options = {}, &block)
  builder = instantiate_builder(record_name, record_object, options, &block)
  output = capture(builder, &block)
  output.concat builder.hidden_field(:id) if output && options[:hidden_field_id] && !builder.emitted_hidden_id?
  output
end

#file_field(object_name, method, options = {}) ⇒ Object

Returns a file upload input tag tailored for accessing a specified attribute (identified by method) on an object assigned to the template (identified by object). Additional options on the input tag can be passed as a hash with options. These options will be tagged onto the HTML as an HTML element attribute as in the example shown.

Using this method inside a form_for block will set the enclosing form’s encoding to multipart/form-data.

Examples

file_field(:user, :avatar)
# => <input type="file" id="user_avatar" name="user[avatar]" />

file_field(:post, :attached, :accept => 'text/html')
# => <input accept="text/html" type="file" id="post_attached" name="post[attached]" />

file_field(:attachment, :file, :class => 'file_input')
# => <input type="file" id="attachment_file" name="attachment[file]" class="file_input" />



752
753
754
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 752

def file_field(object_name, method, options = {})
  InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("file", options.update({:size => nil}))
end

#form_for(record, options = {}, &proc) ⇒ Object

Creates a form and a scope around a specific model object that is used as a base for questioning about values for the fields.

Rails provides succinct resource-oriented form generation with form_for like this:

<%= form_for @offer do |f| %>
  <%= f.label :version, 'Version' %>:
  <%= f.text_field :version %><br />
  <%= f.label :author, 'Author' %>:
  <%= f.text_field :author %><br />
  <%= f.submit %>
<% end %>

There, form_for is able to generate the rest of RESTful form parameters based on introspection on the record, but to understand what it does we need to dig first into the alternative generic usage it is based upon.

Generic form_for

The generic way to call form_for yields a form builder around a model:

<%= form_for :person do |f| %>
  First name: <%= f.text_field :first_name %><br />
  Last name : <%= f.text_field :last_name %><br />
  Biography : <%= f.text_area :biography %><br />
  Admin?    : <%= f.check_box :admin %><br />
  <%= f.submit %>
<% end %>

There, the argument is a symbol or string with the name of the object the form is about.

The form builder acts as a regular form helper that somehow carries the model. Thus, the idea is that

<%= f.text_field :first_name %>

gets expanded to

<%= text_field :person, :first_name %>

The rightmost argument to form_for is an optional hash of options:

  • :url - The URL the form is submitted to. It takes the same fields you pass to url_for or link_to. In particular you may pass here a named route directly as well. Defaults to the current action.

  • :namespace - A namespace for your form to ensure uniqueness of id attributes on form elements. The namespace attribute will be prefixed with underscore on the generated HTML id.

  • :html - Optional HTML attributes for the form tag.

Also note that form_for doesn’t create an exclusive scope. It’s still possible to use both the stand-alone FormHelper methods and methods from FormTagHelper. For example:

<%= form_for @person do |f| %>
  First name: <%= f.text_field :first_name %>
  Last name : <%= f.text_field :last_name %>
  Biography : <%= text_area :person, :biography %>
  Admin?    : <%= check_box_tag "person[admin]", @person.company.admin? %>
  <%= f.submit %>
<% end %>

This also works for the methods in FormOptionHelper and DateHelper that are designed to work with an object as base, like FormOptionHelper#collection_select and DateHelper#datetime_select.

Resource-oriented style

As we said above, in addition to manually configuring the form_for call, you can rely on automated resource identification, which will use the conventions and named routes of that approach. This is the preferred way to use form_for nowadays.

For example, if @post is an existing record you want to edit

<%= form_for @post do |f| %>
  ...
<% end %>

is equivalent to something like:

<%= form_for @post, :as => :post, :url => post_path(@post), :method => :put, :html => { :class => "edit_post", :id => "edit_post_45" } do |f| %>
  ...
<% end %>

And for new records

<%= form_for(Post.new) do |f| %>
  ...
<% end %>

is equivalent to something like:

<%= form_for @post, :as => :post, :url => posts_path, :html => { :class => "new_post", :id => "new_post" } do |f| %>
  ...
<% end %>

You can also overwrite the individual conventions, like this:

<%= form_for(@post, :url => super_posts_path) do |f| %>
  ...
<% end %>

You can also set the answer format, like this:

<%= form_for(@post, :format => :json) do |f| %>
  ...
<% end %>

If you have an object that needs to be represented as a different parameter, like a Person that acts as a Client:

<%= form_for(@person, :as => :client) do |f| %>
  ...
<% end %>

For namespaced routes, like admin_post_url:

<%= form_for([:admin, @post]) do |f| %>
 ...
<% end %>

If your resource has associations defined, for example, you want to add comments to the document given that the routes are set correctly:

<%= form_for([@document, @comment]) do |f| %>
 ...
<% end %>

Where @document = Document.find(params[:id]) and @comment = Comment.new.

Setting the method

You can force the form to use the full array of HTTP verbs by setting

:method => (:get|:post|:put|:delete)

in the options hash. If the verb is not GET or POST, which are natively supported by HTML forms, the form will be set to POST and a hidden input called _method will carry the intended verb for the server to interpret.

Unobtrusive JavaScript

Specifying:

:remote => true

in the options hash creates a form that will allow the unobtrusive JavaScript drivers to modify its behavior. The expected default behavior is an XMLHttpRequest in the background instead of the regular POST arrangement, but ultimately the behavior is the choice of the JavaScript driver implementor. Even though it’s using JavaScript to serialize the form elements, the form submission will work just like a regular submission as viewed by the receiving side (all elements available in params).

Example:

<%= form_for(@post, :remote => true) do |f| %>
  ...
<% end %>

The HTML generated for this would be:

<form action='http://www.example.com' method='post' data-remote='true'>
  <div style='margin:0;padding:0;display:inline'>
    <input name='_method' type='hidden' value='put' />
  </div>
  ...
</form>

Removing hidden model id’s

The form_for method automatically includes the model id as a hidden field in the form. This is used to maintain the correlation between the form data and its associated model. Some ORM systems do not use IDs on nested models so in this case you want to be able to disable the hidden id.

In the following example the Post model has many Comments stored within it in a NoSQL database, thus there is no primary key for comments.

Example:

<%= form_for(@post) do |f| %>
  <% f.fields_for(:comments, :include_id => false) do |cf| %>
    ...
  <% end %>
<% end %>

Customized form builders

You can also build forms using a customized FormBuilder class. Subclass FormBuilder and override or define some more helpers, then use your custom builder. For example, let’s say you made a helper to automatically add labels to form inputs.

<%= form_for @person, :url => { :action => "create" }, :builder => LabellingFormBuilder do |f| %>
  <%= f.text_field :first_name %>
  <%= f.text_field :last_name %>
  <%= f.text_area :biography %>
  <%= f.check_box :admin %>
  <%= f.submit %>
<% end %>

In this case, if you use this:

<%= render f %>

The rendered template is people/_labelling_form and the local variable referencing the form builder is called labelling_form.

The custom FormBuilder class is automatically merged with the options of a nested fields_for call, unless it’s explicitly set.

In many cases you will want to wrap the above in another helper, so you could do something like the following:

def labelled_form_for(record_or_name_or_array, *args, &proc)
  options = args.extract_options!
  form_for(record_or_name_or_array, *(args << options.merge(:builder => LabellingFormBuilder)), &proc)
end

If you don’t need to attach a form to a model instance, then check out FormTagHelper#form_tag.

Form to external resources

When you build forms to external resources sometimes you need to set an authenticity token or just render a form without it, for example when you submit data to a payment gateway number and types of fields could be limited.

To set an authenticity token you need to pass an :authenticity_token parameter

<%= form_for @invoice, :url => external_url, :authenticity_token => 'external_token' do |f|
  ...
<% end %>

If you don’t want to an authenticity token field be rendered at all just pass false:

<%= form_for @invoice, :url => external_url, :authenticity_token => false do |f|
  ...
<% end %>

Raises:

  • (ArgumentError) 


358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 358

def form_for(record, options = {}, &proc)
  raise ArgumentError, "Missing block" unless block_given?

  options[:html] ||= {}

  case record
  when String, Symbol
    object_name = record
    object      = nil
  else
    object      = record.is_a?(Array) ? record.last : record
    object_name = options[:as] || ActiveModel::Naming.param_key(object)
    apply_form_for_options!(record, options)
  end

  options[:html][:remote] = options.delete(:remote) if options.has_key?(:remote)
  options[:html][:method] = options.delete(:method) if options.has_key?(:method)
  options[:html][:authenticity_token] = options.delete(:authenticity_token)

  builder = options[:parent_builder] = instantiate_builder(object_name, object, options, &proc)
  fields_for = fields_for(object_name, object, options, &proc)
  default_options = builder.multipart? ? { :multipart => true } : {}
  output = form_tag(options.delete(:url) || {}, default_options.merge!(options.delete(:html)))
  output << fields_for
  output.safe_concat('</form>')
end

#hidden_field(object_name, method, options = {}) ⇒ Object

Returns a hidden input tag tailored for accessing a specified attribute (identified by method) on an object assigned to the template (identified by object). Additional options on the input tag can be passed as a hash with options. These options will be tagged onto the HTML as an HTML element attribute as in the example shown.

Examples

hidden_field(:signup, :pass_confirm)
# => <input type="hidden" id="signup_pass_confirm" name="signup[pass_confirm]" value="#{@signup.pass_confirm}" />

hidden_field(:post, :tag_list)
# => <input type="hidden" id="post_tag_list" name="post[tag_list]" value="#{@post.tag_list}" />

hidden_field(:user, :token)
# => <input type="hidden" id="user_token" name="user[token]" value="#{@user.token}" />



731
732
733
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 731

def hidden_field(object_name, method, options = {})
  InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("hidden", options)
end

#label(object_name, method, content_or_options = nil, options = nil, &block) ⇒ Object

Returns a label tag tailored for labelling an input field for a specified attribute (identified by method) on an object assigned to the template (identified by object). The text of label will default to the attribute name unless a translation is found in the current I18n locale (through helpers.label.<modelname>.<attribute>) or you specify it explicitly. Additional options on the label tag can be passed as a hash with options. These options will be tagged onto the HTML as an HTML element attribute as in the example shown, except for the :value option, which is designed to target labels for radio_button tags (where the value is used in the ID of the input tag).

Examples

label(:post, :title)
# => <label for="post_title">Title</label>

You can localize your labels based on model and attribute names.
For example you can define the following in your locale (e.g. en.yml)

helpers:
  label:
    post:
      body: "Write your entire text here"

Which then will result in

label(:post, :body)
# => <label for="post_body">Write your entire text here</label>

Localization can also be based purely on the translation of the attribute-name (if you are using ActiveRecord):

activerecord:
  attributes:
    post:
      cost: "Total cost"

label(:post, :cost)
# => <label for="post_cost">Total cost</label>

label(:post, :title, "A short title")
# => <label for="post_title">A short title</label>

label(:post, :title, "A short title", :class => "title_label")
# => <label for="post_title" class="title_label">A short title</label>

label(:post, :privacy, "Public Post", :value => "public")
# => <label for="post_privacy_public">Public Post</label>

label(:post, :terms) do
  'Accept <a href="/terms">Terms</a>.'.html_safe
end



659
660
661
662
663
664
665
666
667
668
669
670
671
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 659

def label(object_name, method, content_or_options = nil, options = nil, &block)
  options ||= {}

  content_is_options = content_or_options.is_a?(Hash)
  if content_is_options || block_given?
    options.merge!(content_or_options) if content_is_options
    text = nil
  else
    text = content_or_options
  end

  InstanceTag.new(object_name, method, self, options.delete(:object)).to_label_tag(text, options, &block)
end

#number_field(object_name, method, options = {}) ⇒ Object

Returns an input tag of type “number”.

Options

  • Accepts same options as number_field_tag



939
940
941
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 939

def number_field(object_name, method, options = {})
  InstanceTag.new(object_name, method, self, options.delete(:object)).to_number_field_tag("number", options)
end

#password_field(object_name, method, options = {}) ⇒ Object

Returns an input tag of the “password” type tailored for accessing a specified attribute (identified by method) on an object assigned to the template (identified by object). Additional options on the input tag can be passed as a hash with options. These options will be tagged onto the HTML as an HTML element attribute as in the example shown.

Examples

password_field(:login, :pass, :size => 20)
# => <input type="password" id="login_pass" name="login[pass]" size="20" />

password_field(:account, :secret, :class => "form_input", :value => @account.secret)
# => <input type="password" id="account_secret" name="account[secret]" value="#{@account.secret}" class="form_input" />

password_field(:user, :password, :onchange => "if $('user[password]').length > 30 { alert('Your password needs to be shorter!'); }")
# => <input type="password" id="user_password" name="user[password]" onchange = "if $('user[password]').length > 30 { alert('Your password needs to be shorter!'); }"/>

password_field(:account, :pin, :size => 20, :class => 'form_input')
# => <input type="password" id="account_pin" name="account[pin]" size="20" class="form_input" />



713
714
715
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 713

def password_field(object_name, method, options = {})
  InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("password", { :value => nil }.merge!(options))
end

#radio_button(object_name, method, tag_value, options = {}) ⇒ Object

Returns a radio button tag for accessing a specified attribute (identified by method) on an object assigned to the template (identified by object). If the current value of method is tag_value the radio button will be checked.

To force the radio button to be checked pass :checked => true in the options hash. You may pass HTML options there as well.

Examples

# Let's say that @post.category returns "rails":
radio_button("post", "category", "rails")
radio_button("post", "category", "java")
# => <input type="radio" id="post_category_rails" name="post[category]" value="rails" checked="checked" />
#    <input type="radio" id="post_category_java" name="post[category]" value="java" />

radio_button("user", "receive_newsletter", "yes")
radio_button("user", "receive_newsletter", "no")
# => <input type="radio" id="user_receive_newsletter_yes" name="user[receive_newsletter]" value="yes" />
#    <input type="radio" id="user_receive_newsletter_no" name="user[receive_newsletter]" value="no" checked="checked" />



864
865
866
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 864

def radio_button(object_name, method, tag_value, options = {})
  InstanceTag.new(object_name, method, self, options.delete(:object)).to_radio_button_tag(tag_value, options)
end

#range_field(object_name, method, options = {}) ⇒ Object

Returns an input tag of type “range”.

Options

  • Accepts same options as range_field_tag



947
948
949
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 947

def range_field(object_name, method, options = {})
  InstanceTag.new(object_name, method, self, options.delete(:object)).to_number_field_tag("range", options)
end

#search_field(object_name, method, options = {}) ⇒ Object

Returns an input of type “search” for accessing a specified attribute (identified by method) on an object assigned to the template (identified by object_name). Inputs of type “search” may be styled differently by some browsers.

Examples

search_field(:user, :name)
# => <input id="user_name" name="user[name]" size="30" type="search" />
search_field(:user, :name, :autosave => false)
# => <input autosave="false" id="user_name" name="user[name]" size="30" type="search" />
search_field(:user, :name, :results => 3)
# => <input id="user_name" name="user[name]" results="3" size="30" type="search" />
#  Assume request.host returns "www.example.com"
search_field(:user, :name, :autosave => true)
# => <input autosave="com.example.www" id="user_name" name="user[name]" results="10" size="30" type="search" />
search_field(:user, :name, :onsearch => true)
# => <input id="user_name" incremental="true" name="user[name]" onsearch="true" size="30" type="search" />
search_field(:user, :name, :autosave => false, :onsearch => true)
# => <input autosave="false" id="user_name" incremental="true" name="user[name]" onsearch="true" size="30" type="search" />
search_field(:user, :name, :autosave => true, :onsearch => true)
# => <input autosave="com.example.www" id="user_name" incremental="true" name="user[name]" onsearch="true" results="10" size="30" type="search" />



890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 890

def search_field(object_name, method, options = {})
  options = options.stringify_keys

  if options["autosave"]
    if options["autosave"] == true
      options["autosave"] = request.host.split(".").reverse.join(".")
    end
    options["results"] ||= 10
  end

  if options["onsearch"]
    options["incremental"] = true unless options.has_key?("incremental")
  end

  InstanceTag.new(object_name, method, self, options.delete("object")).to_input_field_tag("search", options)
end

#telephone_field(object_name, method, options = {}) ⇒ Object Also known as: phone_field

Returns a text_field of type “tel”.

telephone_field("user", "phone")
# => <input id="user_phone" name="user[phone]" size="30" type="tel" />



912
913
914
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 912

def telephone_field(object_name, method, options = {})
  InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("tel", options)
end

#text_area(object_name, method, options = {}) ⇒ Object

Returns a textarea opening and closing tag set tailored for accessing a specified attribute (identified by method) on an object assigned to the template (identified by object). Additional options on the input tag can be passed as a hash with options.

Examples

text_area(:post, :body, :cols => 20, :rows => 40)
# => <textarea cols="20" rows="40" id="post_body" name="post[body]">
#      #{@post.body}
#    </textarea>

text_area(:comment, :text, :size => "20x30")
# => <textarea cols="20" rows="30" id="comment_text" name="comment[text]">
#      #{@comment.text}
#    </textarea>

text_area(:application, :notes, :cols => 40, :rows => 15, :class => 'app_input')
# => <textarea cols="40" rows="15" id="application_notes" name="application[notes]" class="app_input">
#      #{@application.notes}
#    </textarea>

text_area(:entry, :body, :size => "20x20", :disabled => 'disabled')
# => <textarea cols="20" rows="20" id="entry_body" name="entry[body]" disabled="disabled">
#      #{@entry.body}
#    </textarea>



780
781
782
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 780

def text_area(object_name, method, options = {})
  InstanceTag.new(object_name, method, self, options.delete(:object)).to_text_area_tag(options)
end

#text_field(object_name, method, options = {}) ⇒ Object

Returns an input tag of the “text” type tailored for accessing a specified attribute (identified by method) on an object assigned to the template (identified by object). Additional options on the input tag can be passed as a hash with options. These options will be tagged onto the HTML as an HTML element attribute as in the example shown.

Examples

text_field(:post, :title, :size => 20)
# => <input type="text" id="post_title" name="post[title]" size="20" value="#{@post.title}" />

text_field(:post, :title, :class => "create_input")
# => <input type="text" id="post_title" name="post[title]" value="#{@post.title}" class="create_input" />

text_field(:session, :user, :onchange => "if $('session[user]').value == 'admin' { alert('Your login can not be admin!'); }")
# => <input type="text" id="session_user" name="session[user]" value="#{@session.user}" onchange = "if $('session[user]').value == 'admin' { alert('Your login can not be admin!'); }"/>

text_field(:snippet, :code, :size => 20, :class => 'code_input')
# => <input type="text" id="snippet_code" name="snippet[code]" size="20" value="#{@snippet.code}" class="code_input" />



691
692
693
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 691

def text_field(object_name, method, options = {})
  InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("text", options)
end

#url_field(object_name, method, options = {}) ⇒ Object

Returns a text_field of type “url”.

url_field("user", "homepage")
# => <input id="user_homepage" size="30" name="user[homepage]" type="url" />



922
923
924
 
# File 'actionpack/lib/action_view/helpers/form_helper.rb', line 922

def url_field(object_name, method, options = {})
  InstanceTag.new(object_name, method, self, options.delete(:object)).to_input_field_tag("url", options)
end